There are some situations when soft lockup warnings are expected in thekernel. For example, when doing an alt-sysrq-t on a large number of processes,the dump to console can take a long time and the tasklist_lock is held overthat period. This results in a bogus soft lockup warning.

This patch reworks touch_softlockup_watchdog to touch ALL cpu'stouch_timestamp. It also introduces touch_cpu_softlockup_watchdog to toucha single cpu's touch_timestamp. This makes it functionally equivalent totouch_nmi_watchdog.

touch_nmi_watchdog is not modified -- AFAICT it was attempting to touch allcpu's softlockup watchdogs, not just a specific cpu.

/drivers/ide/ide-iops.c does not need to call touch_softlockup_watchdog as itis done in the call to touch_nmi_watchdog.

The EXPORT_SYMBOL for touch_softlockup_watchdog is needed bydrivers/scsi/ips.ko